Rotatable work holder for electroplating apparatus



March 23, 1954 'ROTATABLE WORK HOLDER FOR ELECTROPLATING APPARATUS Filed Jan. 17, 1950 I 3 Sheets-Sheet l hafn ilni [arr BY INVENTOR.

W %M Z March 23, 1954 L. E. COLCLESSER 2,673,076

ROTATABLE WORK HOLDER FOR ELECTROPLATING APPARATUS Filed Jan. 17, 1950 3 Sheets-Sheet 2 o o o o o o o 46 Q 0 o 0 0 0 0 0 0 0 0 6 00006 O o o w 66 5 Ji 0 0 g 0000000000000 oo ooooooooooo 50 0 ooooooo o oooooooooooo 00000000000000 0000000000000 ooooooeooooooo osooooooooooo oooooooogooooo will IHIHIIIIHJIH o 0000 000000000 fi 5,000'000000o000 0000000000000 10 qoo\ o q 9 p ooo i= 0 0000000000000 0000 000000 0 oo 5000 000000 000 o INVENTOR. 54

March 23, 1954 1.. E. COLCLESSER 2,673,076

ROTATABLE WORK HOLDER FOR ELECTROPLATING APPARATUS Filed Jan. 17, 1950 0000000000000 7 0000000000000 000'0 000 0000 000 0000000000000 2000000000000 mnlaJ-ymnnno A .194 Z00 w v 504 1/50 5 h F45 INVENTOR. 56 J56 farflem fikessm BY -22" J m 41 0 90% Patented Mar. 23, 1954 ROTATABLE WORK HOLDER FOR ELECTROPLATING APPARATUS Lorren E. Colclesser, Chicago, Ill., assignor to Merci] Plating Equipment Company, Chicago, 111., a corporation of Illinois Application January 17, 1950, Serial No. 139,050

13 Claims. 1

This invention relates to electroplating apparatus and more particularly to the structure of the plating barrels.

It is an object of the invention to provide an electroplating apparatus of improved construction and improved operating characteristics.

More specifically it is an object of the invention to provide an improved plating barrel construction which plating barrel construction gives increased strength and greater internal volume with the same overall external dimensions used heretofore in the art.

Another object of the invention is to provide an improved plating barrel having a greater area for the transfer of electroplating solution from the in side to the outside of the barrel and vice versa.

A further object of the invention is to provide an improved plating barrel having an increased plating capacity for given overall external dimen- SlOIlS.

Still another object of the invention is to provide a plating barrel having improved means therein for redistributing parts to be plated within the barrel.

A further object of the invention is to provide an electroplating apparatus having a greater plating capacity, an increased operating efiiciency and requiring lower maintenance expenses.

Various other objects, advantages and features of the invention will be apparent from the following specification when taken in connection with the accompanying drawings where certain preferred embodiments are set forth for purposes of illustration.

In the drawings wherein like reference numerals refer to like parts throughout:

Figure l is a general assembly view, partly in section, of an electroplating apparatus constructed in accordance with and embodying the principles of the present invention;

Figure 2 is an end view of the apparatus shown in Figure 1;

Figure 3 is a partial enlarged View in cross-section of a bearing and electrode structure forming a part of the apparatus of Figures 1 and 2;

Figure 4 is a perspective view of a plating barrel made in accordance with and embodying the principles of the present invention;

Figure 5 is a view in vertical cross-section of the plating barrel shown in Figure l;

Figure 6 is a cross-sectional view of the plating barrel shown in Figure 5 as seen in the direction of the arrows along the line 6--G thereof;

Figure 7 is a partial view in cross-section of the barrel shown in Figure 6, illustrating the application of the preferred type of cover clamp;

Figure 8 is a partial view of a plating barrel showing two sides and an end plate thereof in exploded relationship;

Figure 9 is a partial view of a plating barrel showing the manner in which the end plates are secured to the side members;

Figure 10 is an enlarged view of one end of the fastening element shown in Figure 9;

Fi ure 11 is an enlarged partial view in crosssection showing the joint between two sides of the plating barrel; and,

Figure 12 is an enlarged partial view in vertical cross-section of another improved form of electrode structure.

Referring to the drawings and more particu paratus comprises generally a tank 26 adapted to contain a body of electrolyte or plating solution at a suitable level such as indicated at 22. A plating barrel, generally designated by the numeral 24, is rotatably suspended in the body of the electrolyte solution by a pair of hanger arms 26 and 28.

The plating barrel 24 is adapted to contain the articles to be plated, and is rotated by a mechanism to be described hereinafter.

Hanger arms 26 and 28 are suspended from a frame structure which is removably supported on the top of a tank 20 so that the plating barrel with its associated hanger arms and support frame may be removed as a unit from the tank to effect the removal and replacement of the plated articles or articles to be plated from the barrel. The frame structure is supported by brackets 30 and 32 provided on the upper rim of tank 20. These brackets removably receive shafts 34 which form a part of the barrel supporting frame and from which the hanger arms 26 and 2.8 are suspended. The barrel supporting frame also includes a shaft 36 carrying a hook 38 by means of which the frame hanger arms and barrel may be removed from the tank as a unit by any suitable lifting device.

comprises a gear or pulley Ail adapted to be con nected to a suitable source of power. This gear or pulley, as the case may be, is mounted on a stub shaft 42 which is formed as a part of the barrel supporting frame. Shaft 42 also carries a pinion 44 which meshes with a gear 46 suit- Mechanism provided for rotating the barrel ably secured to a trunnion sleeve journaled within a bearing portion 48 formed on the lower end of hanger arm 23. The trunnion sleeve (not shown) and the gear 46 are both secured to the right end plate 50 of the barrel 24, as will be more particularly described hereinafter, whereby the barrel is rotated in response to the movements of gear 46.

The pump 52 driven by an electric motor 54 is provided and connected to a pipe 56 in such a manner as to circulate the electrolyte from the lower portion of tank through a central opening (not shown) in the bearing portion 43 of the hanger sleeve 28 and into the barrel, whereby to effect electrolyte circulation. These details of construction form no part of the present invention except insofar as they cooperate with the structures hereinafter set forth.

The tank 20 carries a pair of support bars 60 from which a plurality of anode bars 62 can be conveniently suspended. The supports 60, which are grounded to the tank 29], form a part of the electrical circuit for the plating current, as is diagrammatically indicated by the wires 64 in Figure 2. The anode bars cooperate with cathode structures carried by the barrel and against which the articles to be plated within the barrel are adapted to engage, the current passing between the cathode and the anode bars through the electrolyte to effect the plating operation, as is well understood in the art. The cathode structures will be more fully described hereinafter.

The rotatable plating barrel 2-4 and its associated'frame structure and hanger arms are electrically insulated from tank 20, one terminal of the electric circuit being connected to the oathode within the plating barrel through the hanger arm 26, as will be described more fully in conjunction with Figure 3.

Referring to Figure 3, there is shown in cross section a cathode contact made in accordance with and embodying the principles of the present invention. This cathode contact is positioned within the left end of barrel 24, and is mounted upon the left end plate 66 thereof. The cathode contact, generally designated by the numeral 68, is substantially circular in shape and is provided with an aperture in the center thereof. A sub stantially laterally extending flange H3 is formed on the circumference of the cathode'contact to give greater contact area, and another flange i2 is formed about the aperture in the center of cathode contact 68. As will be understood, the cathode contact is made of any suitable conducting material.

A conducting trunnion 14 having a boss which extends through the aperture in cathode contact 68 is provided to support the cathode and to provide a means for applying electrical current thereto. A circular-shaped flange '16 extends laterally from the conducting trunnion M and has apertures positioned therein to receive a plurality of screws 18 that fasten the conducting trunnion 14 to a fill-in flange 80 which is made of a suitable non-conducting material such as a plastic. The cathode contact 68 is held in position upon the conducting trunnion 14 and the fill-in flange 80 by means of a bolt 82, which is threadedly received in an aperture in trunnion 14. A plurality of insulating washers 84, 8t and 88 are provided to protect metal parts which are not intended to form part of the cathode contact area from the plating solution. More particularly, washer 88 protects the laterally extending flange 16 of trunnion 14 and the screws 18. Washers 84 and 8% protect the threaded portion of screw 82 and the portion of the trunnion 14 which extends through the aperture in cathode 68. By protecting these exposed metal parts from the electrolyte solution, treeing is prevented or reduced to a minimum. The prevention of treeing greatly facilitates removal, replacement and repair of various cathode parts. It will be seen that bolt 82 secures washers 84, 86 and 88 and the cathode contact 68 in proper relation upon the proper associated parts.

An aperture is formed in end plate 66 to receive a supporting bearing member, and there is also, attached to end plate 56 an apertured flange all which gives added supporting bearing area. A plurality of bolts 92 holds the flange 90 and the end plate 65 in proper relationship so that the apertures therein coincide, and the same bolts 92 attach the flll-in'flange and its associated parts to the end plate 56. The heads of bolts 92 are countersunk, and plugs 94 of insulating material are provided to protect the heads of the bolts from the electrolyte solution whereby to prevent treeing thereon. It will be seen from the above description that end plate 6t and flanges 80 and and associated parts will rotate togetheras a unit when gear 46 is rotated.

The rotatable mounting for the left end of barrel 24 comprises a bearing portion 96 formed on the end of hanger arm 26, a hanger arm trunnion 98 and a bushing I00 which cooperate with the supporting bearing apertures in plate 66 and flange 90 which were described above. All of these parts are made of insulating or non-conducting material such as a plastic. The hanger arm trunnion 98 is substantially circular in cross section, having a flange I02 formed at one end thereof, and fits within a complementarilyshaped aperture in bearing portion 98 with one end thereof extending into the bearing apertures of flange 98 and end plate 66. The bushing member mo is cylindrical in shape and has an aperture formed in the center thereof whereby to allow the bushing to be positioned over the outwardly extending end of the hanger arm trunnion 98. The surface between the bushing I!!!) and the edges of the apertures in end plate 66 and flange 90 form the bearing surface. The hanger arm 26, the hanger arm trunnion 98 and the bushing Hill form the stationary portion of the bearing, with the barrel end 66 and associated parts revolving thereon. A washer "14 is positioned between the end of the hanger arm trunnion 98 and the fill-in flange 80 to provide a bearing surface therebetween, especially in the event that side thrust is encountered.

Electrical current is supplied to the cathode contact 68 through an electrical conductor I06 which is preferably provided with an impermeable insulation such as a rubber cover. The conductor I06 is mounted on the hanger arm 26 and connects with an insulated electrical circuit mounted within the bearing described above. Conductor I06 passe through coinciding apertures in the bearing portion 96 of hanger arm .25 to an axially extending aperture formed in trunnion 98. An insulating tube I08 lines the aperture in trunnion 98 and an insulator bushing llll protects the portion of conductor I08 which is positioned within the aperture of trunnion I08. Electrical connection between conductor I 06 and the conducting trunnion 14 is end members provided by a metallic conducting shaft H2 positioned. within insulator tube Hi8. It will be seen that a complete insulated current. path is provided from the source of current through conductor Hit, shaft H2, and conducting trunnion M. to the cathode contact Ilt. The conducting shaft H2: is. held stationary with respect to the hanger arm 25, while the conducting trunnion M rotates with the plating. barrel. It will thus be seen that a sliding electrical contact is made between the conducting shaft H21 and the conducting trunnion It.

The cathode contact structure shown in Fig ure 3 provides an increased electrode area as compared with electrode structures known heretofore in the art and thus gives more rapid plating and increases the capacity of the plating barrel. It will be seen from Figures 1 and 3 that the entire contacting area of cathode contact 68 i immersed in the electrolyte solution at all times and is never removed therefrom while the barrel is in operation. Positioning the electrode structure on the end plate in the particular structure shown facilitates assembling. and disassembling of the structure for cleaning and repairing. In particular, the cathode contact 63, which is most subject to wear and treeing, can be removed and: replaced by merely unscrewing bolt 32. It further has been found that with cathode structures of th type de scribed the amount of repair and cleaning necessary is materially reduced since all extraneous metal parts are very effectively protected from the electrolyte solution and hence there no tendency. to tree.

Figure 4 is a perspective view of a plating barrel embodying another important feature of the present invention. More specifically, the plating barrel shown in Figure 4 embodies a new manner of joining the sides of the plating barrel whereby to give increased strength in operation and increased capacity and plating rates. The end plates 59 and 66 are substantially heragonal in shape and hold in assembled position the six sides of the plating barrel to form a cylinder of hexagonal cross section. Referring to Figure 6, it will be seen that sides Ild, lit and H53 are identical with the exception of one structural feature and sides lZti and I22 are also identical except for the same structural feature. Side M l will be described in detail and the differences of sides lit i it therefrom will be pointed out.

Referring to Figures 5, 6 and 8, panel section I It comprises generally a rectangularly-shaped frame including a pair of longitudinally extending side members lild Ifii interconnected by l25--l2lil and an intermediate bracing member 532. The two rectangular sec tions thus formed are filled by forarninous sheets I34 and I36. These foraminous sheets are relatively thin compared to the thickness of the frame members, and as may be best seen in Figure 6, are positioned approximately intermediate the depth of the frame whereby to aiford maximum strength and yet provide a maximum internal volume for the assembled barrel. The frame and the foraminous sheets preferably are formed as an integral member, such as by molding 01' casting from a suitable non-conducting material such as a plastic. The longitudinally extending edges of the frame members I21! and I26 are beveled to the proper degree so that the panel sections will fit together.

Means is provided for adjoining adjacent panel sectionsv in the form of a plurality of double dove-tailed key members I38 which cooperate with suitably formed slots in the edges of the panel sections. The key member I38 is an elongated rod whose cross section as seen in Figure 6 is that of two dove-tailed sections joined along the narrow, parallel sides. The longitudinally extending beveled edges of the panel sections are provided with dove-tailed shaped slots extending the length thereof of a size suitable to receive one-half of the key member I 38. When two panel sections are juxtaposed and the key member I38 inserted, it will be seen that the panel sections will be firmly united and will be self-supporting whereby to retain their structural shape. Both of the longitudinally extending, beveled edges of panel sections H4, H6 and He are provided with the above described dovetailed grooves.

Panel sections E20 and I22 are similar in construction to panel section IM and differ therefrom in that only one of the longitudinally extending edges of the frame is provided with a dove-tailed shaped groove.

The end plates 5% and are held in position upon the ends of the assembled panel sections by means of a plurality of tie rods I IB which are positioned in apertures formed in the longitudinally extending edges of the frames of the panel sections. These tie rods I40 extend the length of the panel sections and through both end plates. There is a tie rod positioned in each longitudinally extending side frame member of panel sections H4, H6, H8, I20 and I22. Both ends of the tie rods I40 are threaded to receive nuts Hi2 which are recessed in the end plates iii! and 66. The exposed end of the metallic tie rod its and the metallic nut I42 are covered by an insulating disk I44 which is held position and sealed by a quantity of cement W5. Each end of all the tie rods is constructed in this manner.

The integral construction of the side panels and the positive interlocking of the adjacent edges of the panel gives a plating barrel whose internal volume is greater for the same over-all external dimensions as compared with plating barrels used heretofore. The increased strength of the plating barrel panel sections allows a greater area of perforations therein, thus allowing for a greater flow of plating electrolyte through the barrel, giving a higher plating rate and greater plating capacity. The greater strength of the barrel, especially the additional strength at the interlocking adjacent edges allows heavier loading during operation. as compared with plating barrels known heretofore. The permitted heavier loading in conjunction with the increased volume of the barrel and the increased area of perforation gives a substantial increase in plating capacity, approaching an increase of 50 per cent.

A cover id l is provided to close the opening remaining when panel sections lid, H8, H8, I28 and 5222 are assembled with ends lift and 56. This cover is of substantially the size as the panel sections; having tr longitudinally extending side frame members two end frame members ltd-452 and two reinforcing members Ides-4&6. The rectangular sections so formed are filled with foraininous sheets I88, ill! and I72 in the same manner as described above with respect to panel section lid. The frame members and foraminous sections preferably are made as one piece by molding or casting from a suitable 7 non-conducting material such as a plastic. longitudinally extending edges I56 and I 58 of cover I54 are beveled to the appropriate angle to fit with the beveled edges of panel sections I20 and I22.

As may be best seen in Figure 5, gear 46 is connected to end plate 56 by means of a plurality of bolts I48 which connect with end plate 56 through a series of spacers I56. The heads of bolts I48 are countersunk into the gear 46, and the exposed metallic surface is covered by a plastic insert I52.

There is shown in Figures 1, 4 and 7 a preferred type of clamp for securing the cover I54 in position upon the plating barrel 24. This clamp, generally designated by the numeral I'M, is generally C-shaped and comprises a central body member I16, a hook member H8 formed on one end of the body member H6, and a screw receiving portion I 89. As may be best seen in Figure 7, the central body portion I76 is adapted to overlie the top of cover wt and the hook member I18 engages an inwardly facing edge of the frame of panel section I236. The screw receiving member I86 is provided near its end with a threaded aperture to receive the threaded shank I82 of clamping screw I234. The end of shank I62 bears against an inwardly facing edge of the frame member of panel section I22 when the clamp is in clamping position. When the screw I84 is tightened with the clamp in position, as shown in Figure 7, the cover I54 is held tightly in position, The threads on member I86 and on shank I82 are relatively coarse and heavy to give the necessary strength. The clamp I'M and the screw I84 are both made of a non-conducting material such as a plastic whereby to eliminate treeing. As is illustrated in Figures 1 and 4, preferably at least two clamps are used to properly hold the cover in position during operating of the plating barrel. This particular type of clamp is self-adjusting, since as the parts wear the screw I86 need only be screwed in a greater amount to achieve the desired clamping action, and the clamp in addition is simple, easily manipulated and economical in construction.

Another important feature of the present invention is best illustrated in Figures 5, 6 and 11, and comprises a series of tumbling projections I86, which mix and continuously redistribute the parts being plated as the plating barrel 24 is rotated. Projections I86 are substantially triangular in cross section, as may be seen in Figure 6, and are relatively short as compared to the length of a side of the plating barrel. As shown in Figure 5, a number of tumbling projections I36 are positioned along each edge of the hexagonal plating barrel, a preferred arrangement being three equally spaced tumbling projections at one corner, two equally spaced projections on the next corner, three equally spaced projections on the next corner, etc., around the circumference of the barrel. With such an arrangement, tumbling projections on alternate corners of the barrel are staggered whereby to give a greater distributing and mixing effect. These tumbling projections are preferably formed integral with the panel sections and cover. It is to be understood that the shape, number and arrangement of the tumbling projections may be varied and the particular construction in the drawing has been shown merely for purposes of illustration. The continuous redistribution obtained by the use of tumbling projections I86 gives a more uniform plating The for each piece and allows the use of a shorter plating period to give the necessary minimum required plating to each piece. It will be seen, therefore, that the use of the tumbling projections and the increased rate of flow of electrolyte through the plating barrel which is obtained with the improved panel section construction will give a materially decreased plating period required to give the minimum plating to each work piece.

Figure 12 shows another form of an electrode structure which gives a high cathode contact area and which is particularly useful in the plating of small, relatively light work pieces. The bearing structure associated with this electrode struc ture is similar to the bearing structure described above, which is similar to the electrode structure shown in Figure 3. This bearing structure comprises a bearing portion 96a formed at the lower end of the hanger arm 26a and a hanger arm trunnion 98a, which are mounted in the end plate 66a and its associated insulator washers 90a and 86a. A bearing bushing 16a is interposed between the stationary trunnion 98a and the revolving parts 66a, a and a to provide a suitable bearing surface. The washers 86a and 90a are held in position on the end plate 66a by a plurality of bolts 92a. The heads of the bolts are countersunk into the flange 98a and are protected from the plating solution by non-conducting plugs 94a.

The plating current for the electrode structure is conducted thereto through an insulated conductor I66a, which connects with conducting shaft IIZa that connects with the cathode. A portion of the conductor IIl6a and all of the conductor shaft trunnion 98a and are surrounded and protected by an insulator tube I08a. A bushing IIOa provides support for the conductor I06a near the point of connection between conductor I660. and the conductor bar IIZa. The trunnion 98a, insulator tube IBM and the conductor shaft IIZa are elongated as compared with the corresponding structure in Figure 3 and extend into the barrel a distance away from the end plate 66a.

The end of trunnion 98a which extends into the plating barrel is countersunk to receive the cathode assembly. The cathode plate I86 is in the form of a circular disk having an aperture in the center thereof, and is connected to the conductor shaft II 21 by a cathode connector I88. The cathode connector I88 is generally cylindrical in shape to fit the aperture in the center of cathode plate I86 and has formed on one end thereof a threaded member I96 which is adapted to be screwed into a threaded aperture formed at the end of conductor shaft II2a. To insure a tight fit between the connector shaft H20. and the cathode connector I88, a washer I92 is provided therebetween. The cathode contact plate I86 is only loosely attached to the connector I88, and is held thereon by a non-conducting cap I94 cooperating with a plurality of insulating washers and held in position with a screw I96 which passes through an aperture in cap I94 and threadedly connects with the cathode connector I88. One pair of washers I98200 encircles the cathode connector I88 and is positioned on either side of the cathode plate I86 which extends substantially perpendicularly with respect to the axis of connector I83. A second pair of washers 202204 encircle the first set of washers I93 and j 200 and are also positioned one on either side of the cathode plate I86.

IIZa are positioned within the Support for the cathode plate I86 is provided by two disk-like washers 2062B8, which sup port the cathode plate I86 on both sides thereof.

All of the Washers [98-200, 202-404 and B-2ll8 and the cathode plate We are held in position by the cap I94 and bolt [fit described above. This arrangement of the cap and washers insures that only the outer portions of the cathode plate I86 come into contact with the plating solution and thus prevent treeing around the points of interconnection between the various metallic parts. With such a manner of assembly, the cathode structure is easily disassembled for repair and replacement.

The path for current from the conductor itlic to the cathode plate I86 is through the conductor bar 2a and the cathode connector 588. It is contemplated that an electrode structure will be positioned at both ends of the plating barrel.

Each electrode structure is preferably positioned from the nearest'end plate approximately onethird of the length of the plating barrel. In this electrode structure the cathode plate I85 is completely immersed in the electrolyte solution during all the time that the plating barrel is in operation. This cathode structure provides a high plating area and makes possible the use of a simpler bearing support structure.

There has been provided a plating barrel construction and electrode structure whichfulfills all of the above objects. More particularly, the barrel structure gives a barrel having the increased strength and greater internal volume for the same over-all external dimensions as compared with plating barrels used heretofore in the art. The greater strength of the plating barrel allows a heavier loading and also permits the use of a larger area of perforations in the panel sections. The combination of the heavier load ing, the greater internal volume and the greater area for circulation of electrolyte solution gives approximately a per cent increase in plating capacity per barrel. The improved electrode structure is easier to assemble and disassemble,

and provides a greater contact area, which in turn produces a higher plating rate. The provision of tumbling projections ives improved distribution of the parts being plated during the plating operation and gives a more uniform plating to each work piece in a shorter plating period.

It is obvious that various changes may be made in the specific embodiments set forth for purposes of illustration without departing from the spirit of the invention. The invention is accordingly not to be limited to the specific embodi ments shown and described but only as indicated in the following claims.

The invention is hereby claimed as follows:

1. A plating barrel for use in electrolytically plating articles comprising a plurality of panel sections, the longitudinally extending adjacent edges of said panel sections being adapted to fit with one another whereby to form a cylindrical barrel, certain of said adjacent edges having a greater thickness than mid portions of the panel sections and having keying grooves formed therein, and keying members positioned within the keying grooves in adjacent panel edges to hold said panel edges in juxtaposed assembled position.

2. A plating barrel for us in electrolytically plating articles comprising a plurality of onepiece panel sections, the longitudinally extending adjacent edges of said panel sections having a greater thickness than mid portions of the panel sections and being adapted to fit with one another whereby to form a cylindrical barrel, certain of said adjacent edges having keying grooves formed therein, and keying members shaped to fit within the keying grooves in adjacent panel edges whereby to hold said panel edges in juxtaposed assembled position.

3. A plating barrel for use in electrolytically plating articles comprising a plurality of plastic panel sections, the longitudinally extending adjacent edges of said panel sections having a greater thickness than mid portions of said panel sections and being adapted to fit with one another whereby to form a cylindrical barrel, certain of said adjacent edges having keying grooves formed therein, and keying members shaped to fit within the keying grooves in adjacent panel edges whereby to hold said panel edges in juxtaposed assembled position.

4. A plating barrel for use in electrolytically plating articles comprising a plurality of onepiece plastic panel sections, the longitudinally extending adjacent edges of said panel sections having a greater thickness than mid portions of said panel sections and being adapted to fit with one another whereby to form a cylindrical barrel, certain of said adjacent edges having keying grooves formed therein, and keying members shaped to fit within the keying grooves in adjacent panel edges whereby to hold said panel edge in juxtaposed assembled position. i

5. A panel section for plating barrels used in electrolytically plating articles comprising relatively thick plastic frame members extending longitudinally of the panel section, and. relatively thin plastic foraminous sheet material joining said frame members, said frame members and foraminous sheet being formed integral.

6. A panel section for plating barrels used in electrolytically plating articles comprising relatively thick frame members adapted to lie sub- {stantially parallel with respect to the axis of the plating barrel, and relatively thin foraminous sheet means connecting said frame members and filling the space therebetween, at least one of said frame members having a keying groove formed along the longitudinally extending edge thereof.

7. A panel section for plating barrels used in electrolytically plating articles comprising a substantially rectangular relatively thick plastic frame member and a relatively thin plastic foraminous sheet covering the area defined by said frame member and connected to said frame member outwardly of inner surfaces of said frame member, said frame member and said foraminous sheet being formed integral.

8. A panel section for plating barrels used in electrolytically plating articles comprising a substantially rectangular relatively thick frame member, and a relatively thin foraminous sheet covering the area defined by said frame member and connected to said frame member, said frame member having an interlocking keying groove formed along at least one of the longitudinally extending edges thereof.

9. A panel section for a rotatable plating barrel used in electrolytically plating articles comprising a substantially rectangular relatively thick frame member, a relatively thin foraminous sheet disposed within said frame member and filling the area defined thereby, and work tumbling means formed on said frame member and adapted to protrude into a plating barrel when said panel section is assembled with other panel sections to form a complete plating barrel, said frame member and foraminous sheet and work tumbling means being formed integral.

10. A plating barrel for use in electrolytically plating articles comprising a rotatable multisided cylindrical barrel having a plurality of corners, relatively short tumbling projections disposed in the corners of said barrel and projecting inwardly toward the longitudinal axis thereof, the tumbling projections in alternate corners of the barrel being disposed toward the ends of the barrel and the projections on the barrel and the other two projections being disposed toward the ends of the barrel, th other corners of said barrel having two tumbling projections thereon, the last mentioned tumbling projections being positioned longitudinally of the barrel at places intermediate the first mentioned tiunbling projections.

12. A panel section for plating barrels used in electrolytically plating articles comprising a substantially rectangular frame member, and a foraminous sheet covering the area defined by said frame member and integrally connected to said frame member, said frame member having a dovetail shaped keying groove formed along at least one of the longitudinally extending edges thereof.

13. A plating barrel for us in electrolytically plating articles, comprising a plurality of panel sections disposed to provide a multi-sided barrel, the adjacent marginal edges of said panel sections having a greater thickness than mid portions of said panel sections, said mid portions having inner surfaces spaced radially outwardly of inner surfaces of said marginal edges, said adjacent marginal edges having keying grooves therein, and keying means disposed in said grooves tohold said panel section edges in juxtaposed assembled position.

LORREN E. COLCLESSER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 138,319 Dextor Apr. 29, 1873 668,720 Siegmund Feb. 26, 1901 694,565 Mason Mar. 4, 1902 2,315,272 Potthoff Mar. 30, 1943 2,334,919 Godfrey Nov. 23, 1943 2,480,022 Hogaboom Aug. 23, 1949 FOREIGN PATENTS Number Country Date 44,797 Denmark Nov. 2, 1931 

